1. Field of the Invention
This invention relates to a process for the production of pure epidermal growth factors in high yield from crude extracts of the submaxillary glands of adult male mice.
2. Description of the Prior Art
In 1962, Stanley Cohen in the Journal of Biological Chemistry, Vol. 237, page 1555, reported the isolation from the submaxillary glands of adult male mice of a polypeptide which stimulates the proliferation of various epidermal and epithelial tissues both in vivo and in vitro. The isolated polypeptide has been termed epidermal growth factor and studies on its biological properties, biosynthesis and mechanism of action have been reviewed in Cohen, S. and Taylor, J. M., "Epidermal Growth Factor; Chemical and Biological Characteristics", Epidermal Wound Healing, edited by Maibach and Rovee, 1972 Yearbook Medical Publication, page 203.
More recently, tests with rabbits have demonstrated that topical application of the epidermal growth factor to cornea whose epithlium has been scraped off accelerates its regrowth. Experimental Eye Research, Vol. 15, pages 361-366 (1973).
Methods for the isolation of epidermal growth factor have been discussed in the 1962 Cohen article, supra and also in Taylor, J. M., Cohen, S., and Mitchell, W. M. (1970) Proc. National Academy of Science, U.S.A. Vol. 67, page 164 and Taylor, J. M., Mitchell, W. M. and Cohen, S. (1972), Journal of Biological Chemistry, Vol. 247, pages 5928-5934. The yields produced by these methods, however, are low and in addition the methods involve multistep procedures which are cumbersome and time-consuming.
It is an object of this invention to provide a process for increasing the yields of epidermal growth factor isolatable from the submaxillary glands of adult male mice.
It is also an object of the invention to achieve such improved yields while at the same time greatly simplifying the isolation by considerably reducing the multistep procedures heretofore required for the isolation of such epidermal growth factor.
Yet another object of the invention is to provide a derivative of the epidermal growth factor which is indistinguishable in biological activity from epidermal growth factor.